The capacitors and inductors have the I-V characteristics that change with the applied voltage, current and time. The I-V characteristic is nonlinear and is a function of time.

To illustrate the I-V characteristics of a capacitor we would need a three-dimensional diagram including both the time-current and time-voltage graphs.

However, like the linear and nonlinear components, the capacitor and inductor must be stored in the system equations.

During transient analysis, the solution points are discrete moments in time. At each timepoint, the numeric integration routines determine linear I-V relationship for capacitors and inductors. For a capacitor this linear relationship is given (at each timepoint) by:

The conductance and current source value for capacitors, and resistance and voltage source values are recalculated at each new simulation timepoint by numeric integration algoritms. Once determined they are stored into the corresponding system matrices.